Table 4. — Coefficients of the weight-length relation for blue marlin, sailfish, and striped 

 marlin from the eastern Pacific, (log weight = a + b (log length)). 





Measurement 



















a 



b 



Range of 

 length (cm) 



N 





Species 



Length (cm) 



Weight 



r 



Blue marlin 

















Female 



Eye-fork 



kg 



-5.690 



3.318 



154.0-265.1 



57 



0.948 





Eye-fork 



lb 



-5.347 



3.318 



154.0-265.1 



57 



0.948 





Snout-fork 



kg 



-7.543 



3.905 



221.1-347.3 



20 



0.954 





Snout-fork 



lb 



-7.199 



3.905 



221.1-347.3 



20 



0.954 



Sailfish 

















Male 



Eye-fork 



kg 



-4.396 



2.643 



115.1-196.5 



367 



0.867 





Eye-fork 



lb 



-4.057 



2.643 



115.1-196.5 



367 



0.867 





Snout-fork 



kg 



-5.286 



2.873 



183.0-260.2 



24 



0.910 





Snout-fork 



lb 



-4.946 



2.873 



183.0-260.2 



24 



0.910 



Female 



Eye-fork 



kg 



-4.084 



2.507 



123.1-221.7 



435 



0.812 





Eye-fork 



lb 



-3.739 



2.507 



123.1-221.7 



435 



0.812 





Snout-fork 



kg 



-4.059 



2.356 



201.7-271.0 



47 



0.835 





Snout-fork 



lb 



-3.714 



2.356 



201.7-271.0 



47 



0.835 



Combined 

















sexes 



Eye-fork 



kg 



-4.360 



2.628 



115.1-221.7 



802 



0.846 





Eye-fork 



lb 



-4.017 



2.628 



115.1-221.7 



802 



0.846 





Snout-fork 



kg 



-4.788 



2.662 



183.0-271.0 



71 



0.890 





Snout-fork 



lb 



-4.446 



2.662 



183.0-271.0 



71 



0.890 



Striped marlin 

















Male 



Eye-fork 



kg 



-5.005 



2.999 



119.6-202.6 



975 



0.877 





Eye-fork 



lb 



-4.664 



2.999 



119.6-202.6 



975 



0.877 





Snout-fork 



kg 



-5.166 



2.903 



172.0-261.0 



220 



0.780 





Snout-fork 



lb 



-4.857 



2.903 



172.0-261.0 



220 



0.780 



Female 



Eye-fork 



kg 



-5.243 



3.113 



110.0-215.1 



1,007 



0.854 





Eye-fork 



lb 



-4.900 



3.113 



110.0-215.1 



1,007 



0.854 





Snout-fork 



kg 



-5.267 



2.950 



153.0-271.0 



315 



0.778 





Snout-fork 



lb 



-4.914 



2.950 



153.0-271.0 



315 



0.778 



Combined 

















sexes 



Eye-fork 



kg 



-5.157 



3.071 



110.0-215.1 



1,982 



0.864 





Eye-fork 



lb 



-4.816 



3.071 



110.0-215.1 



1,982 



0.864 





Snout-fork 



kg 



-5.340 



2.982 



153.0-271.0 



535 



0.784 





Snout-fork 



lb 



-5.007 



2.982 



153.0-271.0 



535 



0.784 



weight-length relations, transformations of the data 

 were not necessary because plots of the data on 

 eye-fork length indicated that they were reasonably 

 linear. Equations for converting fork length and 

 mandible-fork length are given in Table 3. 



The equation used in the analyses, except that for 

 weight, was Y = a + bX, where Y = morphometric 

 character measured in centimeters, and a and b = 

 constants that are determined by least-squares pro- 

 cedures. For weights, the equation log Y = a + 

 b\ogX, where Y = weight, X = body length, and a 

 and b = constants, was used. Weight-length rela- 

 tions based on weight in kilograms and pounds and 

 body length as eye-fork length and snout-fork 



length are summarized in Table 4 for blue marlin, 

 sailfish, and striped marlin. Statistical tests were 

 performed to test the hypotheses that the intercept 

 of the regression, a, is zero and that the slope of the 

 regression, b, is zero for all regressions except 

 those for weight-length. 



All plots of the data were based on averages of 

 5-cm groupings of eye-fork length. 



BLUE MARLIN 



A total of 57 blue marlin was sampled at Buena 

 Vista and Mazatlan. The average length was 206 cm 

 at Buena Vista and 209 cm at Mazatlan (Fig. 1). 



Ill 



